It’s a long journey from your first day of work to retirement. And like all long journeys, it’s important to plan ahead so you know whether you’re still on schedule to reach your final destination. Think about a train timetable and you’ll have a suitable picture in your head.

To help keep people on track when saving for retirement, one large investment firm put together a timetable with savings milestones you should strive to reach as you get older.

They recommend starting to save at age 25 and take the fullest advantage of tax-advantaged retirement savings plans like an IRA and 401k. They assume you’ll save 6% of your salary the first year and ramp that up by 1% annually until you reach a savings rate of 12%. The timetable also assumes that you’ll earn 5.5% annually on your diversified investments, grow your salary by 1.5% and retire at 67 with an annual income of 85% of your most recent salary.

With those assumptions, you should have saved 1X your current salary by age 35, 3X your current salary by 45, 5X your current salary by 55 and 8X your final salary at retirement (age 67).

Don’t be discouraged if you’re not on schedule. It’s only a guideline ;with many, many variables, and a skilled financial advisor can provide advice ;to help you along the way, especially when deciding when to retire.

So let’s look at some important pieces of the retirement planning timetable that aren’t judgment calls; they’re written into the law.

Age 50

You can now contribute ;$24,000 per year in a company-sponsored retirement plan (e.g., a 401k or 403b), and $6,500 in an IRA. That’s $6,000 and $1,000 more, respectively, than what younger workers are able to save in retirement plans.

Age 55

If you retire, quit or are laid off, you can take 401k withdrawals from the account at your most recent job without paying the 10% early withdrawal penalty. IRA withdrawals will generally still carry the 10% penalty tax, although you ;can withdraw contributions made to a Roth IRA at anytime without penalty (withdrawing earnings prior to age 59.5 will incur a penalty).

Age 59½

You no longer have to pay the 10% early withdrawal penalty on 401k distributions, but you do still have to pay income tax at your current rate, which could be raised by the withdrawal. You can also take withdrawals without penalty from your IRA, as long as the money has been invested for at least five years.

Age 62

You become eligible for Social Security benefits, but your payments will be reduced by as much as 30% if you start this young. If you work while you’re collecting Social Security at this age, part or all of your payments may be temporarily withheld until you reach full retirement age.

Age 65

This is when you become eligible for Medicare. You can sign up as early as three months before your 65th birthday for coverage to begin the month you turn 65. Medicare is a great program, and since ;health care can become hugely expensive as you get older, it’s an irreplaceable part of your retirement planning. Don’t miss your dates. A little bit of reading will make this complex subject simpler. A great place to start is at www.medicare.gov.

Age 66

You’re eligible to collect the full amount of Social Security you’ve earned if you were born before 1955. Add two months to 66 if you were born in 1955, four months for 1956, six months for 1957, eight months for 1958, 10 months for 1959.

Age 67

People born in 1960 or later are eligible to collect the full amount of Social Security; if they sign up at 66 they’ll get 6.7% less than if they wait until 67.

Age 70

Delaying claiming Social Security will increase your payments by 8 percent per year until age 70. There’s no additional benefit to postponing payments after 70, so you shouldn’t delay receiving benefits past this point.

Age 70½

You have to begin withdrawing money from traditional IRAs and 401ks; these are known as required minimum distributions (RMDs). You have to pay income tax on the withdrawal (ideally less than what you would have paid had you still been working), and if you miss the withdrawal date or withdraw too little, the penalty is 50% of what you should have withdrawn. Don’t miss the date or the correct amount on this one; it’ll be expensive. It is your responsibility, not the IRS’s, to ensure you’re fulfilling your RMD requirements. Remember that once you withdraw the money, you can reinvest it wherever you want.

If this sounds complicated, remember that a skilled financial advisor can help you. Think about this timetable as background, so that when your advisor discusses stops along your retirement journey, you’ll be right alongside, knowing where you’re going.