4 mistakes that derail new managers (and how to fix them before it's too late)

There's a predictable pattern to how new managers will fail.

Month one, they're excited. Month three, they're overwhelmed. Month six, their team is underperforming and they're working 60-hour weeks. By month nine, either they quit or you're wondering if you made the wrong call.

The frustrating part? Most of these failures follow the same script. Same mistakes. Same warning signs. Same preventable disaster.

The even more frustrating part? Most organizations see it happening and do nothing until it's too late.

Here are the four mistakes that tank new manager transitions—and how to catch them before they become unfixable problems.

Mistake one: Letting them manage the way they were managed

Your new manager had a boss once. Maybe several. Some were great. Some were terrible. And whether they realize it or not, those experiences shaped their mental model of what management looks like.

The problem? Bad management habits get passed down like family recipes. Your new manager might think micromanaging is "being thorough" because that's what their old boss did. They might avoid giving feedback because their previous manager only spoke up during performance reviews. They might think being available 24/7 is what commitment looks like.

Just because someone survived a terrible manager doesn't mean they should manage the same way.

How to fix it:

Interrupt this cycle with training on what good management actually looks like. Show them different models. Let them try new approaches.

Before they start managing, ask them directly: "Tell me about the best manager you ever had. What did they do that worked? Now tell me about the worst. What would you do differently?"

This conversation surfaces their assumptions. It gives you a chance to reality-check their management philosophy before it affects their team.

Then give them frameworks for the basics:

• What a good one-on-one looks like
• How to structure feedback conversations
• When to delegate and when to jump in
• How to set clear expectations without micromanaging

Don't assume they know this stuff. Most people have never been taught how to manage well.

Mistake two: Assuming they'll ask for help

Most new managers think they should already know how to do this. After all, you promoted them because they were good at their job. Asking for help feels like admitting they weren't ready.

So they don't ask. They struggle in silence. They Google "how to handle underperforming employees" at 11 PM. They second-guess every decision. And by the time you realize they're struggling, bad habits are already entrenched.

This plays out in predictable ways:

They avoid hard conversations because they don't know how to start them. They either over-delegate or under-delegate because they're not sure what the right balance is. They burn out trying to do their old job and their new job simultaneously.

How to fix it:

Create structures that normalize getting support:

• Required training: Make it mandatory, not optional. When everyone has to attend new manager training, it's not a sign of weakness.
• Mandatory mentor check-ins: Assign a mentor and schedule their first three meetings. Don't leave it up to the new manager to reach out.
• Regular cohorts: Put new managers in a group together. When they hear that everyone else is also confused about how to handle a specific situation, they relax.

Make it clear that learning management skills is part of the job, not a sign of weakness.

Your new managers need to hear you say: "This is hard. Everyone struggles with this at first. Here's how we're going to support you."

And then actually follow through.

Mistake three: Not adjusting their workload

You can't add management responsibilities on top of a full individual contributor workload and expect both to go well.

But that's exactly what most companies do. Your new manager gets promoted, their team expands and suddenly they're responsible for five people's growth, performance and wellbeing. On top of their existing project load.

What happens? They keep doing what they know. They stay late to finish their individual work. They skip one-on-ones because they're behind on deliverables. They jump in to do the work themselves because it's faster than coaching someone through it.

And then everyone wonders why they're not "stepping up" to management.

How to fix it:

When someone becomes a manager, their capacity for hands-on work drops. Plan for it.

Before the promotion, sit down and map out their current responsibilities. Which projects can they hand off? Which client relationships need to transition? What individual contributor work should move to someone else on the team?

Then actually make those changes. Don't just talk about it.

Redistribute projects. Reset expectations with stakeholders. Give them space to actually do the job you promoted them to do.

In their first 90 days as a manager, they should be spending:

• 50% of their time on their team (one-on-ones, coaching, feedback)
• 30% on strategic work (planning, priorities, cross-functional alignment)
• 20% on hands-on technical work (maintaining credibility, handling complex problems)

If their calendar doesn't reflect this, their workload needs adjustment.

Mistake four: Waiting too long to course-correct

If a new manager is struggling, address it in month two, not month ten.

The longer bad habits solidify, the harder they are to fix. Your manager starts micromanaging, and by month six, their team has learned to wait for direction instead of taking initiative. They avoid feedback conversations, and now there's six months of unaddressed performance issues to untangle.

Early problems are fixable. Late problems require intervention.

But most organizations wait until the annual review to give feedback. By then, the damage is done. The manager is either defensive or defeated. Their team has learned to work around them. And you're stuck with a difficult conversation that could have been avoided.

How to fix it:

Regular check-ins with their manager should include:

• How are you spending your time?
• What's working?
• What feels hard?
• Where do you need more support?

These check-ins should happen weekly for the first month, then biweekly for the next three months.

Watch for early warning signs:

• They're working longer hours than before the promotion
• They're still doing mostly individual contributor work
• Their team is coming to you instead of to them
• They're avoiding difficult conversations
• They're not delegating effectively

When you spot these patterns, address them immediately. Not with criticism, but with support and redirection.

"I noticed you've been staying late to finish the Johnson project yourself. Let's talk about how to coach Sarah through that instead. What would she need from you to take it on?"

Catch problems early. Adjust quickly.

What good support looks like

These four mistakes are common. They're also preventable.

When you promote someone to manager, you're asking them to learn a completely new skill set. That requires support, not just a title change.

Good support means:

• Training before, during and after the transition
• Clear expectations about what changed
• Reduced individual contributor workload
• Regular check-ins and feedback
• A mentor who's been there before
• Permission to be new at something

When you get this right, your new managers don't just survive the transition. They thrive in it. Their teams grow. Projects move forward. And you build a pipeline of strong leaders who know how to develop the people around them.

When you skip this support, you lose good people. Your star performer burns out. Their team suffers. And eventually, someone leaves—often the person you just promoted.

The difference between these two outcomes comes down to recognizing these mistakes early and fixing them before they become patterns.

Start paying attention now. Your new managers need you to.

‍