A professor started pursuing financial independence at 38. A 7-step ladder helped him go from debt to 'lean FI.'

Miguel Marquez has spent years making complex subjects easier to understand.

Originally from Spain, the 47-year-old earned a Ph.D. in French linguistics from Indiana University Bloomington and now teaches French, Spanish, and personal finance at a university in Shenzhen, China.

Through teaching personal finance and pursuing financial independence himself, Marquez has learned that saving for such a distant goal can feel either too intimidating to begin or too tedious to sustain over decades.

He found a way to make the process more manageable by using "financial freedom milestones," a concept he first discovered on the Money Flamingo blog. Rather than treating financial independence as one enormous — and potentially unachievable — target, the framework divides the journey into seven stages.

"It's like playing a video game," he said, with each milestone representing another level of financial security.

Marquez, who began seriously pursuing financial independence after completing his Ph.D. at 38, explained the seven milestones he uses to track his progress.

1. Debt freedom

The first milestone is eliminating debt. Marquez said he borrowed money only once, during his fourth year at university, and quickly decided it was not something he wanted to get used to: "I didn't like the feeling."

He's been debt-free since completing his undergraduate degree, meaning he had already cleared the first milestone before he began deliberately pursuing financial independence.

2. 'F-you money'

The next stage is accumulating "F-you money," typically defined as having enough savings to leave an unfulfilling job, take a career break, or make another major life change without facing immediate financial consequences.

Definitions vary, but Marquez follows the version popularized by JL Collins, author of "The Simple Path to Wealth": roughly one year of living expenses set aside.

That cushion creates options, Marquez said: "If you're in a job you don't like, you can say, 'I'm leaving.' You can look for a different job, become self-employed, or do whatever you want to do."

3. Coast FI

Reaching Coast FI means you have invested enough that, assuming your portfolio continues compounding, it's projected to grow into the amount you'll need by traditional retirement age — without requiring further contributions.

That can free up income for other priorities, since you no longer need to save as aggressively for retirement.

Marquez said he reached Coast FI in June 2024, less than two years after moving to China for his current teaching position. He was in his mid-40s.

4. Flamingo FI

About a year later, Marquez reached "Flamingo FI," another concept developed by the Money Flamingo blog.

At that point, he'd saved about half of his full FI target — or roughly 12.5 years of annual expenses under the conventional 4% rule. The name comes from the idea that you've reached FIRE "standing on one leg," like a flamingo.

5. Lean FI

Marquez is currently at Lean FI, a form of financial independence in which investments can cover essential living costs while leaving relatively little room for discretionary spending. He said his portfolio, worth nearly $400,000, can support housing, food, fixed expenses, and an occasional short trip.

His low cost of living in Shenzhen is an important part of the calculation. He lives in subsidized housing on his university campus and said he can cover his annual expenses with just 30% of his income.

6. Full financial independence

The next stage is full financial independence, sometimes simply called FI or traditional FIRE.

Under the 4% rule, you're generally considered financially independent once you've saved about 25 times your annual expenses. You can then withdraw 4% in your first year of retirement and adjust future withdrawals for inflation.

7. Fat FI

The final milestone is Fat FI: having enough invested to support a lifestyle with considerably more discretionary spending than traditional financial independence. While there is no universal threshold, some investors define it as a portfolio large enough to cover two or three times their normal expenses, while others use a specific net-worth target.

Marquez said he's not compelled to reach Fat FI. Because his living costs are comparatively low, he expects ordinary financial independence to provide him with a lifestyle that already feels abundant.

Chunking out his journey into smaller milestones helped him reach a level of financial security he once assumed was out of reach on a teaching salary.

"I thought that you needed a lot of money to solve the money problem," Marquez said. "But when I started calculating and writing down what I would actually need, I thought, 'Wait a second — this is feasible.'"