ATD OrgDev runs at the Indiana Convention Center in Indianapolis. The venue lists the event from September 29 to October 1, 2026, with sessions in Sagamore 1-7 and a forecast attendance of 1,000 (icclos.com). The event page also carries a September 30 to October 1 line in its body copy, so confirm the session days with your delegates' registration before you fix the room nights. One person inside the company holds the rooms, and that person carries a block of fifteen to forty rooms for a learning delegation that travels as a small group.
What the venue publishes
The Indiana Convention Center sits at 100 South Capitol Ave, Indianapolis, IN 46225. The telephone number is (317) 262-3400. The programme covers organization development practice, with sessions on culture, talent strategy and management, leadership and employee development, and human resources. Delegates assess their current organizational structures, build programmes tied to their organization's goals, and network with peers.
The venue's calendar carries two other events across the same three days: the MAPP Benchmarking and Best Practices Conference and ATD Core4. Three programmes in one building thicken demand on the room nights you need.
The downtown room supply
Four published numbers shape a block in Indianapolis. Downtown holds 7,100 hotel rooms, and skywalks connect 4,700 of those rooms to the Convention Center. Downtown holds 200 restaurants within walking distance, and Indianapolis International Airport sits 15 minutes away (icclos.com).
The skywalk figure matters to a delegation that walks to Sagamore 1-7 each morning.
Fifteen to forty rooms on a Sunday to Thursday pattern
A Sunday arrival with a Thursday release holds four nights: Sunday September 27, Monday September 28, Tuesday September 29 and Wednesday September 30. The delegation checks out on Thursday October 1.
Build the count from your own delegate list. Anyone who must be in the room for the first session needs the night before it. Anyone arriving on the opening morning needs no night at all. Test the two early nights against your travel plan, and ask the property whether the group rate covers a colleague who joins for part of the stay only.
Colleagues who arrive on different flights
A delegation of fifteen to forty people rarely lands together. One colleague flies in on the Sunday, another lands on the Monday night, a third drives in. Hold every one of them under a single booking reference.
Give the property one reference, one group name and one group contact. Each arrival then reads as part of the block. Ask the property to record that reference on every reservation in the delegation, and ask what the front desk does with a colleague who arrives without it.
Send the rooming list as one row per guest per stay. Put the arrival date and the departure date on every row. Some rows will show a Sunday arrival, some a Monday arrival, and some a guest who shares with another.
Ask for the rooming list deadline and the name-change deadline in the same reply. Ask who may authorise a name change and what the property charges for one. Ask how a colleague who arrives a day early is handled, and whether that extra night takes the group rate.
Splitting one master account afterwards
The block is held on one master account. The company pays once, and the internal split happens after the delegation has left.
Ask the property for sub-accounts, sometimes called sub-folios or cost centres, mapped to the departments that send people. Each delegate's charges then post to the right sub-account at check-in.
Two questions settle the split before anyone arrives. Which charges ride on the master account? Which charges does each delegate settle personally? A parking charge, a catering charge or a room-service charge placed on the group account becomes a rebilling exercise later.
Ask for the final invoice as one document with each sub-account listed separately. Ask for the deadline to dispute a line on it, and ask who at the property may authorise a charge to a sub-account after checkout.
Deposit, attrition and the cut-off
Ask for the deposit as an amount, a due date and a destination. That destination may be the first night, the whole stay or a separate holding sum. Ask which one, and ask who signs for it.
Attrition is the payment a group makes when it uses fewer rooms than the block promised. Ask for the percentage, the date the shortfall is measured, whether the count runs in rooms or room nights, and the rate a shortfall is charged at. Those four answers produce four different invoices.
The cut-off date returns unsold rooms to general inventory. Ask for the date, the time of day and the person who can move it. Ask whether a name added after the cut-off still receives the group rate.
A block of fifteen rooms absorbs a shortfall badly, because one dropped room is close to seven per cent of the block. Settle the attrition percentage before you fix the count.
The one item to confirm in writing
Before you commit, ask the property to put one thing in a single written reply: the room nights the group is responsible for, the rate a shortfall is charged at, and the date that shortfall is measured. Ask the same reply to name the sub-accounts the master account will split into.
Send the request by email and keep the reply with the signed contract. Every other number in the block follows from that reply.